Effects of global warming on humans - Wikipedia
Human activities contribute to climate change by causing changes in Earth's atmosphere in the amounts of greenhouse gases, aerosols (small particles), and . human-induced climate change causes global warming, but what is not Heat waves nearly always occur in association with a strong. Unprecedented warming; Direct evidence of human contribution to atmospheric CO2; Natural and human factors that influence the climate.
Direct evidence of human contribution to atmospheric CO2 Carbon dioxide concentrations. Climate Central Carbon dioxide CO2 is the main heat-trapping gas largely responsible for most of the average warming over the past several decades. The atmospheric concentration of CO2 has increased dramatically, from a pre-industrial era AD — concentration of approximately parts per million ppm to today's ppm.
Scientists warned for years about this dangerous threshold, but with the accelerated pace of emissions the question changed from whether we would reach CO2 concentrations above ppm to when. The Arctic reached ppm in In the Mauna Loa Observatory in Hawaii recorded more than ppm. In March global averages reached this threshold, and in September the world reached a point of no-return: CO2 concentration levels are unlikely to dip below ppm again.
While the concentration of carbon has increased, the carbon originating from natural sources has decreased. Scientists can tease apart how much CO2 comes from natural sources, and how much comes from combusted fossil fuel sources. This information tells scientists that fossil fuel emissions are the largest contributor of CO2 concentrations since the pre-industrial era. Volcanic events and some types of human-made pollution, both of which inject sunlight-reflecting aerosols i.
Human activity drives climate change. History of Climate Drivers: Volcanic eruptions account for the cooling spikes seen in the graph in and IPCC AR 5 Among natural drivers, a large volcanic eruption can have a sharp cooling influence as it spews tiny particles high into the stratosphere the layer of the atmosphere above the troposphere where weather typically occurs.
The massive explosions from Krakatoa Indonesia in and Mount Pinatubo Philippines infor example, can be seen as the two largest downward spikes in the volcanic data depicted in the figure to the right.
How Do We Know that Humans Are the Major Cause of Global Warming? | Union of Concerned Scientists
These particles prevented the full energy of the sun from reaching the surface of Earth and created a cooling trend for several years.
Fossil fuel burning by humans emits tiny particles in addition to releasing CO2 in the atmosphere. Some particles reflect sunlight back to space aerosolssimilar to the volcanic particles, having a cooling effect.
Other particles such as soot black carbon absorb the sunlight and drive temperature rise, leading to local warming of the atmosphere level where the soot particles circulate. Very likely, there would have been even more warming in the past 60 years if it were not for these human-made and natural tiny particles. Much as the Air Force develops computer programs to simulate aircraft flight under different conditions, climate scientists develop computer programs to simulate global climate changes under different conditions.
Most of those compelled to leave their homes eventually returned when conditions improved, but an undetermined number became migrants, usually within their country, but also across national borders.
It is highly exposed to climate impacts, and is home to highly vulnerable population groups, who are disproportionately poor and marginalized. Tuvalu already has an ad hoc agreement with New Zealand to allow phased relocation.
They are not willing to leave their homes, land and families. Even where there is awareness many believe that it is a problem caused by developed countries and should therefore be solved by developed countries.
Some experts even support migration as an appropriate way for people to cope with environmental changes. However, this is controversial because migrants — particularly low-skilled ones — are among the most vulnerable people in society and are often denied basic protections and access to services. Climate security Climate change has the potential to exacerbate existing tensions or create new ones — serving as a threat multiplier.
It can be a catalyst for violent conflict and a threat to international security. The Military Advisory Boarda panel of retired U. One study found no statistically meaningful relationship between climate and conflict using data from Europe between the years and Climate change's impact as a security threat is expected to hit developing nations particularly hard. In Britain, Foreign Secretary Margaret Beckett has argued that "An unstable climate will exacerbate some of the core drivers of conflict, such as migratory pressures and competition for resources.
Experts have suggested links to climate change in several major conflicts: War in Darfurwhere sustained drought encouraged conflict between herders and farmers    Syrian Civil Warpreceded by the displacement of 1. Climate change and poverty and Climate change and gender The consequences of climate change and poverty are not distributed uniformly within communities. Individual and social factors such as gender, age, education, ethnicity, geography and language lead to differential vulnerability and capacity to adapt to the effects of climate change.
Climate change effects such as hunger, poverty and diseases like diarrhea and malaria, disproportionately impact children; about 90 percent of malaria and diarrhea deaths are among young children.
Children are also 14—44 percent more likely to die from environmental factors,  again leaving them the most vulnerable. Those in urban areas will be affected by lower air quality and overcrowding, and will struggle the most to better their situation.
List of costliest Atlantic hurricanes and Physical impacts of climate change As the World Meteorological Organization explains, "recent increase in societal impact from tropical cyclones has largely been caused by rising concentrations of population and infrastructure in coastal regions. The s and s were notable because of the extremely low amounts of damage compared to other decades. The decade — has the second most damage among the past 11 decades, with only the decade — surpassing its costs.
The cost is also increasing partly because of building in exposed areas such as coasts and floodplains. The ABI claims that reduction of the vulnerability to some inevitable effects of climate change, for example through more resilient buildings and improved flood defences, could also result in considerable cost-savings in the longterm. Sea level rise and Future sea level A major challenge for human settlements is sea level riseindicated by ongoing observation and research of rapid declines in ice-mass balance from both Greenland and Antarctica.
Estimates for are at least twice as large as previously estimated by IPCC AR4, with an upper limit of about two meters. Coasts and low-lying areas[ edit ] For historical reasons to do with trademany of the world's largest and most prosperous cities are on the coast. In developing countries, the poorest often live on floodplainsbecause it is the only available space, or fertile agricultural land.
These settlements often lack infrastructure such as dykes and early warning systems.
How Do We Know that Humans Are the Major Cause of Global Warming?
Poorer communities also tend to lack the insurance, savings, or access to credit needed to recover from disasters. In a journal paper, Nicholls and Tol considered the effects of sea level rise: Small islands and deltaic settings stand out as being more vulnerable as shown in many earlier analyses. Collectively, these results suggest that human societies will have more choice in how they respond to sea-level rise than is often assumed.
However, this conclusion needs to be tempered by recognition that we still do not understand these choices and significant impacts remain possible. The IPCC reported that socioeconomic impacts of climate change in coastal and low-lying areas would be overwhelmingly adverse. The following impacts were projected with very high confidence: By the s, millions of people would experience floods every year due to sea level rise. The numbers affected were projected to be largest in the densely populated and low-lying mega-deltas of Asia and Africa; and smaller islands were judged to be especially vulnerable.
A study in the April issue of Environment and Urbanization reports that million people live in coastal areas within 30 feet 9. Energy sector[ edit ] Oil, coal and natural gas[ edit ] Oil and natural gas infrastructure is vulnerable to the effects of climate change and the increased risk[ citation needed ] of disasters such as stormcyclonesflooding and long-term increases in sea level.
Minimising these risks by building in less disaster prone areas, can be expensive and impossible in countries with coastal locations or island states. All thermal power stations depend on water to cool them. Not only is there increased demand for fresh water, but climate change can increase the likelihood of drought and fresh water shortages.
Another impact for thermal power plants, is that increasing the temperatures in which they operate reduces their efficiency and hence their output.
The source of oil often comes from areas prone to high natural disaster risks; such as tropical storms, hurricanes, cyclones, and floods. An example is Hurricane Katrina 's impact on oil extraction in the Gulf of Mexicoas it destroyed oil and gas platforms and damaged more.
However, the impact of water shortages on nuclear power plants cooled by rivers will be greater than on other thermal power plants. This is because old reactor designs with water-cooled cores must run at lower internal temperatures and thus, paradoxically, must dump more heat to the environment to produce a given amount of electricity.
This situation has forced some nuclear reactors to be shut down and will do so again unless the cooling systems of these plants are enhanced to provide more capacity. Such shutdowns happened in France during the and heat waves. During the heat waves, 17 reactors had to limit output or shut down.
Human activities are impacting the climate system.
Other Cases have been reported from Germany, where extreme temperatures have reduced nuclear power production 9 times due to high temperatures between and Similar events have happened elsewhere in Europe during those same hot summers. Many scientists agree that if global warming continues, this disruption is likely to increase. Lower river flows because of drought, climate change, or upstream dams and diversions, will reduce the amount of live storage in a reservoir; therefore reducing the amount of water that can be used for hydroelectricity.
The result of diminished river flow can be a power shortage in areas that depend heavily on hydroelectric power. The risk of flow shortage may increase as a result of climate change. The results are rising insurance premiums, and the risk that in some areas flood insurance will become unaffordable for those in the lower income brackets. Financial institutions, including the world's two largest insurance companies: